Recent Accounting Pronouncements and Changes To Accounting Policies - Additional Information (Detail) - Increase (decrease) due to application of IFRS 9 [member] $ in Millions	Jan. 01, 2018 CAD ($)
Disclosure of financial assets at date of initial application of IFRS 9 [line items]
Investments reclassified from AFS to FVPL	$ (49.4)
Unrealized gains on reclassification	$ 0.9

The amount of non-current financial assets mandatorily measured at fair value through profit or loss in accordance with IFRS 9. [Refer: Financial assets at fair value through profit or loss, mandatorily measured at fair value]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2018-01-01
-Paragraph 8
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2018-03-01&anchor=para_8_a&doctype=Standard
-URIDate 2018-03-16

Name:	ifrs-full_NoncurrentFinancialAssetsAtFairValueThroughProfitOrLossMandatorilyMeasuredAtFairValue
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant